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Modern Batteries and Winter Storage Headaches

New chemistries have created new challenges

No, this isn’t about electric cars. Just because you don’t own an electron-power automobile doesn’t mean you’re able to ignore the world of battery chargers. Modern automobiles carry a plethora of power-robbing electronics that can suck down the battery when left unattended for significant periods of time.

In Michigan, the snow and salt of winter forces many owners to store their modern and classic sports cars in a nice, cozy garage or warehouse. Unfortunately, it’s getting more and more complicated to figure out what battery maintainer—trickle charger—to connect to your car as it hides from old man winter.

A friend of mine recently purchased a new 2018 Mercedes-AMG GT C Roadster. With winter whipping around outside his home, it’s going to sit still until spring arrives. He had a factory Mercedes charger from his 2014 Mercedes E63 AMG sitting around and planned to use that on the GT C. However, his OCD friend (read: me) knew that the new convertible comes with a lithium-ion battery and his old maintainer isn’t compatible with the lighter, more expensive setup.

Confusingly, the latest Mercedes trickle charger that’s happy to play in the world of lithium-ion looks identical to the older Mercedes charger outside of the part number. Plus, the only way to know the old maintainer doesn’t jive with the latest battery tech is to read the manual. Unfortunately, a Mercedes dealer I called was no help in confirming as they didn’t know this bit of information.

More recently, my friend also bought a new 2018 Mercedes-AMG E63 S. Upon arrival, we had to work with the parts department at the dealer to figure out what type of battery was fitted to the 603-hp sedan. We finally figured out that the E63 uses a more conventional AGM—absorbent glass mat—battery, which is compatible with both the old and new battery maintainer.

Speaking of AGM batteries, Optima sells a unique type of AGM battery featuring spiral-wound cells versus the flat-plate design used on traditional AGM batteries. If your car came with or, more likely, has an Optima-type replacement battery, it’s a good idea to use a charger that’s fully compatible. You can buy one from Optima but many CTEK-brand battery chargers carry the “snowflake” mode—the setting for Optima-type AGM batteries or low-temperature charging (below 41 degrees F). CTEK calls the Optima-type battery a ‘power AGM battery’. Just make sure to toggle the mode button to the snowflake icon each time you plug-in the charger.

Speaking of charging, if you read the manual for most battery maintainers, you’ll see that you must plug the chargers into the car first and then the outlet. That’s slightly unconventional and likely not something most people do. A friend of mine was having dead battery issues with his Ferrari F12 until the dealer told him that he had to make sure to first plug the factory battery maintainer into the car and then the wall. But if you own a Lamborghini Huracan, you must plug the factory charger into the wall first or else it won’t charge the car.

Make sure you’re writing this all down as there will be a quiz tomorrow.

Getting back to lithium-ion batteries, a person I know bought a BMW M4 GTS when it first came out. I went with him to the dealer to get a battery charger for the limited-edition M4 but, at the time, BMW didn’t offer a trickle charger that was compatible with lithium-ion batteries and he bought a CTEK lithium-ion battery maintainer instead. Upon reading through the manual, however, we learned that the CTEK charger is only compatible with lithium-ion batteries. So, don’t plug that charger into any other cars.

It’s not just high-end vehicles that are complicating the world of batteries. The new Hyundai Ioniq Hybrid doesn’t come with a conventional starter battery and, as such, there are no jump-starting posts. If the engine fails to start due to battery discharge, there’s a button you car press inside the cabin to send some juice from the 240-volt electric motor battery pack to the small, low-voltage, lithium-ion starter battery to get you on your way.

If you plan to not drive your car regularly, make sure you buy a dedicated battery maintainer specifically designed for your vehicle. When you sell the car, include that charger with the car and educate the new buyer on the setup. If you own multiple cars, use a label maker to clearly mark each charger so you know what car each matches and what the recommended plug-in procedure is—either plugging into the wall or vehicle first. Each and every time you park the car for an extended period of time, make sure the car is connected to battery maintainer correctly. Trust me, you don’t want to deal with the headaches of a dead battery or the cost of replacing a battery, especially as they go more sophisticated and expensive.